1. Field of the Invention
This invention relates to capacitance gauging apparatus for the calibration of surface shapes and determination of load distribution between meteable surfaces.
2. Description of the Prior Art
Many rotating apparatus have thrust bearing pads that are accurately machined and lapped. Bearing surfaces and runners that mate therewith sustain less operating friction and thus increase the efficiency of the utilizing apparatus when the pads are flat or nearly so. To insure mating surface flatness the bearing pads are periodically inspected to determine their flatness. Inspection procedures of the past have commonly involved using large straight edges and feeler papers. Such measuring instruments have inherent disadvantages since the straight edges cover only a small percentage of the area to be inspected making the inspection procedure very time consuming and the results dependent upon the inspector's skill since a great deal of human judgment is needed in using the feeler papers to determine the size of the separation gap between the bearings and runners.
Copending Patent Application Ser. No. 723,269, filed Sept. 15, 1976, U.S. Pat. No. 4,103,226, and assigned to the assignee of the present invention discloses an apparatus for gauging the texture of a conductive surface. The probe of the texture gauging device determines, on a minute scale, the finish or texture of the surface in question and is unsuitable for determining general surface conditions, shapes, or configurations. FIG. 2 of the previously mentioned prior art Patent Application graphically illustrates the minute surface measuring features made possible by the included deformable elastomer.
While surface finish is often important, the general character or shape of mateable surfaces is also important. Prior attempts to accurately measure such general surface characteristics have disadvantages which include high operator skill levels, readings which are often ambiguous and require interpretation, and high cost which is justifiable only in large laboratories, machine shops, or manufacturing facilities.